Earlier this year, researchers provided evidence for expression of TIGIT to mark senescent and exhausted T cells in the immune systems of older individuals. Here, new results reinforce the point that TIGIT-expressing T cells are a burden. These cells cause issues, contributing to the inflammatory and weakened state of the aged immune system. Selectively destroying them should help, and senolytic drugs may achieve this goal, as least insofar as the biochemistry of TIGIT-expressing T cells overlaps with that of better studied varieties of senescent cell in tissues. To what degree this is the case remains to be determined; researchers in the cellular senescence field have far more analysis of this nature in front of them than can possibly be accomplished over the next few years, and this particular case is probably still a fair way down the list by priority.
Researchers have identified that an immune cell subset called gamma delta T cells that may be causing and/or perpetuating the systemic inflammation found in normal aging in the general geriatric population and in HIV-infected people who are responding well to drugs. The team measured many markers on the surface of immune cells in the blood of people either with or without HIV (uninfected controls) that were sub-divided into two groups: younger (less than 35 years) and older (over 50 years) and compared that data with levels of inflammatory proteins in their plasma.
Researchers found a marker on these gamma delta T cells, called TIGIT, that tracked significantly with plasma inflammatory markers in both the HIV+ and uninfected subject groups, and therefore could be targeted to potentially stop this "inflammaging" found in both HIV+ people and the general geriatric population. "Our study indicates that there's a previously uninvestigated cell subset new player in the immune landscape that could be driving widespread illnesses and with targeted gamma delta therapeutics maybe there may be a chance of reducing onset, symptoms, and/or severity of inflammation-related diseases."